1) Field of the Invention
The present invention relates to a bar-code reader and a computer product that read a bar-code with improved accuracy.
2) Description of the Related Art
Conventionally, in a field of products distribution, a bar-code provided on a product is read optically, and information related to the product such as a price and a name of the product is recorded in a register.
In a bar code, information related to a product is encoded as characters, and is a combination of alternate black and white bars. In a bar-code reader, light beam emitted from a laser diode is made to scan the bar code, reflected light of the beam is received, and bar-code information is read from an electric signal corresponding to width of black bars and white bars.
The bar code is printed on various media such as an organic material, a can, and paper. Therefore, in conventional bar code printing, depending on the medium, there may occur an error in width of bars due to stains during distribution or due to blurring. Errors in width of the bar result in erroneous reading by the bar-code reader.
Therefore, the bar-code reader is shipped from its manufacturing factory in a condition with a tolerance such that setting conditions of parameters necessary for reading the bar-code are relaxed for a standardized width error.
However, after the shipment of the bar-code reader, there are often inferior bar codes that have a width error beyond specifications. In such a case, the bar-code cannot be read no matter for how long it is scanned, and an operator has to input bar-code information. Consequently, that takes too much of operation time.
Moreover, if the frequency of inability to read the inferior bar code increases, a user of the bar-code reader complains to a manufacturer. The manufacturer has to send a person-in-charge to a site to investigate and take measures, or to carry the bar-code reader to the manufacturer for thorough investigation and take measures, thereby causing a demerit to both the user and the manufacturer.